134879-54-2Relevant articles and documents
Attempted synthesis of 1,3,5-triphenyl-2,4,9-trithia-1,3,5-triplumbaadamantane. Decomposition of organolead iodides
Kobayashi, Michio,Latour, Stéphan,Wuest, James D.
, p. 2908 - 2913 (1991)
MNDO calculations suggest that the strength of the bridgehead carbon-hydrogen bond in 2,4,9-trithia-1,3,5-triplumbaadamantane (2a) should be only 54 kcal/mol and the hydride affinity of the corresponding bridgehead cation 2a+ should be only 215 kcal/mol. As a donor of hydrogen atoms or hydride, plumbaadamantane 2a should therefore be even more reactive than the analogous stannaadamantane 1a. Unfortunately, substituted derivative 2b could not be prepared from (Ph3PbCH2)3CH by controlled iodinolysis followed by treatment of the intermediate hexaiodide (PhI2PbCH2)3CH with Ph3SnSSnPh3. This failure results in part from the tendency of organolead diiodides R2PbI2 to undergo redistribution reactions that produce unstable triiodides RPbI3. Diiodides capable of intramolecular redistributions are particularly reactive. The resulting triiodides then decompose by a formal reductive elimination of RI and PbI2. Since the iodinolysis of (cyclopropylmethyl)triphenylplumbane (11) yields mainly (iodomethyl)cyclopropane instead of ring-opened products derived from cyclopropylmethyl cations or radicals, we suggest that the reductive elimination of RI and PbI2 from RPbI3 is concerted.
